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Finding the Fourth Proportional to 424.29, 636.70 and 420.81

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Solution

The fourth proportional to 424.29, 636.70 and 420.81 is: 631.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    424.29 : 636.70 = 420.81 : x
  2. Step 2: Convert to fraction form
    424.29/636.70 = 420.81/x
  3. Step 3: Cross multiply
    424.29x = 636.70 × 420.81
  4. Step 4: Simplify right side
    424.29x = 267,930.27
  5. Step 5: Solve for x
    x = 267,930.27/424.29
  6. Step 6: Final answer
    x = 631.49

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.